Wide color-gamut vehicle infotainment display system with quantum dot element

ABSTRACT

A display device includes a planar array of blue light-emitting diodes (LEDs) that are each configured to generate a blue output light, wherein the planar array is positioned parallel to a light-receiving surface of a liquid crystal module and a nanocrystal material that is disposed between the planar array and the liquid crystal module, and the liquid crystal module. The nanocrystal material is configured to: receive the blue output light, convert a first portion of the blue output light to a green light emission, convert a second portion of the blue output light to a red light emission, and transmit a remainder portion of the blue output light. The liquid crystal module is configured to generate an image that includes a portion of the green light emission, a portion of the red light emission, and a portion of the remainder portion of the blue output light.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of the co-pending U.S. patentapplication titled, “WIDE COLOR-GAMUT VEHICLE INFOTAINMENT DISPLAYSYSTEM,” filed on Oct. 30, 2017 and having application Ser. No.15/570,741 which is a national stage application of the internationalapplication titled, “WIDE COLOR-GAMUT VEHICLE INFOTAINMENT DISPLAYSYSTEM,” filed on May 27, 2016 and having Application No.PCT/US2016/034867, which claims the benefit of United States provisionalapplication titled, “ENHANCED VEHICLE INFOTAINMENT DISPLAY SYSTEM,”filed on May 29, 2015 and having Application No. 62/168,673. The subjectmatter of these related applications is hereby incorporated herein byreference.

BACKGROUND Field of the Various Embodiments

The various embodiments relate generally to automotive design and, morespecifically, to a wide color-gamut vehicle infotainment display systemwith quantum dot element.

Description of the Related Art

In-vehicle infotainment (IVI) systems, also referred to as in-carentertainment (ICE) systems, may include various types of hardwaredevices and/or software modules that are integrated with or added tovehicles to enhance the driver and/or passenger experience. IVI systemshave become a common feature in modern automobiles and other forms oftransportation and may provide audio or video entertainment, automotivenavigation, driver assistance, video gaming capability, Internetconnectivity, and the like to passengers and drivers.

IVI systems typically include a display screen, such as a liquid crystaldisplay (LCD) screen. One well-known drawback of LCD-based displayscreens is that such display screens have a relatively limited colorgamut, which is the specific range of colors reproducible by the screenwithin the visible spectrum. For example, LCD-based display screens mayhave a color gamut of 72-74% of the National Television System Committee(NTSC) standard color gamut, which itself only includes a portion of allcolors identifiable by the human eye. Consequently, some colors cannotbe accurately displayed. As a result, if such colors are outputted forrendering via such a display, the colors will appear washed out and/orwill be inaccurately displayed, degrading the viewing experience for IVIsystem users.

Another drawback with many LCD-based display screens is that thebacklighting elements of such displays are generally arranged along anedge of the display screen. As a result, these backlighting elements arenecessarily disposed near the touch-sensitive surface of the displayscreen, causing the touch-sensitive surface to be undesirably warm.

Accordingly, what would be useful is a vehicle infotainment displayhaving improved color properties and temperature characteristics.

SUMMARY

The various embodiments set forth a display device that includes adisplay device that comprises a planar array of blue light-emittingdiodes (LEDs) that are each configured to generate a blue output light,wherein the planar array is positioned parallel to a light-receivingsurface of a liquid crystal module and a nanocrystal material that isdisposed between the planar array and the liquid crystal module, and theliquid crystal module. The nanocrystal material is configured to:receive the blue output light, convert a first portion of the blueoutput light to a green light emission, convert a second portion of theblue output light to a red light emission, and transmit a remainderportion of the blue output light. The liquid crystal module isconfigured to receive the green light emission, the red light emission,and the remainder portion of the blue output light and generate an imagethat includes a portion of the green light emission, a portion of thered light emission, and a portion of the remainder portion of the blueoutput light.

At least one advantage of the disclosed embodiments is that a vehicleinfotainment display device can output more vibrant colors thanwhite-LED-based display devices. Further advantages are that, duringoperation, a touch-sensitive surface of the display device does notbecome uncomfortably warm, and components of the display deviceexperience less thermal stress.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

So that the manner in which the above recited features of the variousembodiments can be understood in detail, a more particular descriptionof the various embodiments, briefly summarized above, may be had byreference to embodiments, some of which are illustrated in the appendeddrawings. It is to be noted, however, that the appended drawingsillustrate only typical embodiments and are therefore not to beconsidered limiting of its scope, for the various embodiments may admitto other equally effective embodiments.

FIG. 1 is a block diagram illustrating a vehicular infotainment systemconfigured to implement one or more aspects of the various embodiments;

FIG. 2 is an exploded view of a display device of the vehicularinfotainment system of FIG. 1, according to the various embodiments;

FIG. 3 is a partial schematic side view of the display device of thevehicular information system of FIG. 1, according to the variousembodiments;

FIG. 4 is a graph illustrating the spectral power distribution of alight source juxtaposed with the multiple passbands of a color filterassembly included in the display device of FIGS. 2 and 3, according tothe various embodiments; and

FIG. 5 is a block diagram illustrating the vehicular infotainment systemof FIG. 1 in communication with an electronic control module of avehicle, according to the various embodiments.

FIG. 6 is an exploded view of a display device, according to the variousembodiments.

FIG. 7 is a partial schematic side view of the display device of FIG. 6,according to the various embodiments.

FIG. 8A is a partial schematic side view of an augmented blue LED thatincludes a quantum dot layer formed within an LED assembly, according tovarious embodiments.

FIG. 8B is a partial schematic side view of an augmented blue LED thatincludes a quantum dot layer formed on an outer surface of an LEDassembly, according to various other embodiments.

FIG. 8C is a partial schematic side view of an augmented blue LED thatincludes quantum dots or crystals formed within a transparent case of anLED assembly, according to various other embodiments.

FIG. 9 is a partial schematic side view of a display device thatincludes a curved light guide plate, according to the variousembodiments.

FIG. 10 is a partial schematic side view of a display device thatincludes a planar array of blue LEDs, according to the variousembodiments.

FIG. 11 is a partial schematic side view of a display device thatincludes a planar array of blue LEDs, according to the various otherembodiments. For clarity, identical reference numbers have been used,where applicable, to designate identical elements that are commonbetween figures. It is contemplated that features of one embodiment maybe incorporated in other embodiments without further recitation.

DETAILED DESCRIPTION

FIG. 1 is a block diagram illustrating a vehicular infotainment system100, configured according to various embodiments. Infotainment system100 may be any technically feasible in-vehicle infotainment (IVI) systemassociated with a particular vehicle, and may include, withoutlimitation, audio and/or video players, a video game console, one ormore display devices, voice-recognition software, and the like.

In some embodiments, vehicular infotainment system 100 providesnavigation information and other vehicle control information to a driveroperating a vehicle. Specifically, for navigation, vehicularinfotainment system 100 may be configured to accept input from a driveror other person (a “user” 101), including a destination location, toanalyze road information, to calculate or determine one or more drivingpaths for the driver, to display such driving paths overlaid on a map,and to output associated driving instructions to the driver.Alternatively or additionally, vehicular infotainment system 100 may beconfigured to display controls to user 101 for controlling variousequipment and devices within the vehicle. Such equipment and devices mayinclude, without limitation, radio and other audio devices, multi-mediaplayers, wireless Internet devices, in-vehicle network devices,environmental control systems, cellular phone or other wirelesscommunication devices, and the like.

In some embodiments, vehicular infotainment system 100 is integrated inor includes a head unit of an automotive stereo system, and may beconfigured as a subsystem of a vehicle control system associated withthe vehicle and share computational resources therewith. In otherembodiments, vehicular infotainment system 100 is implemented as astand-alone or add-on feature, part of the original equipmentmanufacturer (OEM) controls of the vehicle, or a combination of both.

As shown, vehicular infotainment system 100 may include, withoutlimitation, a central processing unit (CPU) 110, a graphics processingunit (GPU) 120, system memory 130, input devices 140, one or moredisplay devices 150, storage 160, and a global positioning system (GPS)receiver 170.

In operation, the CPU 110 is the master processor of the infotainmentsystem 110, controlling and coordinating operation of other systemcomponents. In particular, the CPU 110 receives input via input devices140 and executes infotainment software 131 to output navigation andother infotainment-oriented information to display device 150.

CPU 110 may be any suitable programmable processor implemented as a CPU,an application-specific integrated circuit (ASIC), a field programmablegate array (FPGA), any other type of processing unit, or a combinationof different processing units. In general, CPU 110 may be anytechnically feasible hardware unit capable of processing data and/orexecuting software applications to facilitate operation of vehicularinfotainment system 100 as described herein. GPU 120 may be any suitableprogrammable or fixed function processor that accepts commands and datafrom CPU 110 and generates images for display on display device 150.System memory 130 stores, among other things, infotainment software 131,which includes, without limitation, software for controlling thedifferent equipment and devices associated with infotainment system 110,described above. System memory 130 generally comprises storage chipssuch as random access memory (RAM) chips that store applications anddata for processing by CPU 110.

Input devices 140 enable user 101 to provide input to vehicularinfotainment system 100 and/or CPU 110. Thus, via user input devices140, user 101 may select navigational targets, initiate telephone calls,and otherwise interact with vehicular infotainment system 100. Userinput devices 140 may include, without limitation, one or moremicrophones 141 and/or keypads 142. Microphone 141 enablesvoice-activated instructions to be received by vehicular infotainmentsystem 100, while keypad 142 enables instructions to be entered viaphysical gestures on a touch-sensitive screen or actuation/depression ofmechanical buttons. In some embodiments, keypad 142 may be configured asselectable alpha-numeric characters or soft keys displayed on atouch-sensitive screen. In such embodiments, the selectablealpha-numeric characters may be displayed by display device 150 or on aseparate display device. Alternatively or additionally, keypad 142 maybe configured with mechanical keys, such as a keyboard, or any othermechanical controller, such as a video gaming console. In someembodiments, one or more mechanical buttons of keypad 142 are located onthe steering wheel of the vehicle or any other location separate from analpha-numeric portion of the keyboard. For example, but withoutlimitation, such separately located buttons may include on/off buttons,select buttons, mode change buttons, and the like.

Display device 150 may be a video display screen configured to presentvideo media to user 101, such as output from a back-up camera,navigation information, entertainment content, environmental controlsystem information, etc. Display device 150, along with one or more userinput devices 140, may be integrated into a dashboard of the vehicleassociated with vehicle infotainment system 100 or as an instrumentcluster display. In some embodiments, display device 150 is notincorporated into vehicle infotainment system 100, and may instead be aseparate device. For example, and without limitation, display device 150may be a component of a stand-alone navigation system. In someembodiments, display device 150 is configured with a touch-sensitivescreen, and consequently may also be used as an input device by user101. For example, and without limitation, in such embodiments, user 101may make selections and/or enter data into vehicle infotainment system100 via the touch interface 142 of display device 150. Embodiments ofdisplay device 150 are described in greater detail below in conjunctionwith FIGS. 2 and 3.

In various embodiments, storage 160 includes non-volatile memory such asoptical drives, magnetic drives, flash drives, or other storage. GPSreceiver 170 determines global position of the vehicle associated withvehicular infotainment system 100 based on one or more GPS satellites,various electromagnetic spectrum signals (such as cellular towersignals, wireless Internet signals, and the like), or other signals ormeasurements, or on a combination of the above items. In variousembodiments, infotainment software 131 accesses global positioninginformation from GPS receiver 170 to determine a current location of thevehicle.

FIG. 2 is an exploded view of display device 150, according to variousembodiments, and FIG. 3 is a partial schematic side view of displaydevice 150, according to various embodiments. Display device 150includes, without limitation, a back light unit (BLU) 210, a quantum dot(QD) material 220, a color filter assembly 230, and a liquid crystal(LC) panel 240, arranged as shown.

In the embodiment illustrated in FIGS. 2 and 3, BLU 210 provides anevenly-lit surface that acts as a light source of blue, polarized lightfor display device 150. BLU 210 may include, without limitation, a backpanel 211 and a plurality of blue light-emitting diodes (LEDs) 212disposed on one or more edges of back panel 211, such as gallium nitride(GaN) LEDs. In some embodiments, the blue light that is emitted by blueLEDs 212 and directed into back panel 211 has a wavelength between about450 nm and about 495 nm. In some embodiments, the plurality of blue LEDsmay be disposed on two opposing internal edges of back panel 211, or onall four internal edges of back panel 211.

Back panel 211 may include, without limitation, a reflector panel 219disposed on the rear surface of back panel 211, at least one polarizingfilter 213, a light guide plate 214, a diffuser film 215, and a prismfilm 216. Alternatively, light guide plate 214 and diffuser film 215 maybe combined as a light diffuser element. For clarity, polarizing filter213, light guide plate 214, diffuser film 215, and prism film 216 areomitted from FIG. 2. Polarizing filter 213 properly polarizes lightemitted from BLU 210, and is typically positioned between QD substrate220 and BLU 210. Light guide plate 214 evenly distributes incident lightfrom blue LEDs 212 across an emission surface 217 of BLU 210, via totalinternal reflection and in combination with extraction featuresincorporated in light guide plate 214 (such as a dot or groove pattern).Diffuser film 215 eliminates the dot pattern that may be included inlight emitted from light guide plate 214, and prism film 216 increasesthe perpendicular component of the direction vector of emitted light toemission surface 217, since light typically emerges from light guideplate 214 at various angles. Thus, while light produced by blue LEDs 212may enter back panel 211 along one or more edges, the blue polarizedlight leaving BLU 210 via emission surface 217 is bright and uniform inintensity, and somewhat perpendicular to emission surface 217.

QD substrate 220 converts part of the light emitted by BLU 210 intorelatively pure green light and red light by the appropriatelyconfigured quantum dots, thereby enabling an efficient display withenhanced color properties. For example, in some embodiments, QDsubstrate 220 is an organic substrate, such as a polyimide film, inwhich quantum dots or quantum rods are embedded. A quantum dot is asemiconductor nanocrystal that is small enough to exhibit quantummechanical properties, where the electronic characteristics of thequantum dot are closely related to the size and shape of the quantumdot. Specifically, the band gap in a quantum dot, which determines thefrequency range of emitted light, is inversely related to the size ofthe quantum dot, so that larger quantum dots emit longer wavelengths(e.g., red), while smaller quantum dots emit shorter wavelengths (e.g.,green). Consequently, when a suitable number of quantum dots of asuitable size, shape, and composition are embedded in QD substrate 220,a selected portion of incident blue light from BLU 210 is converted intored light and into green light.

Because quantum dots naturally produce monochromatic light, they can beused to generate a spectrum of light that can be accurately matched withthe colors of the filters in color filter assembly 230. Consequently,BLU 210, in conjunction with QD substrate 220, can provide a moreefficient light source than white-LED-based light sources, whichgenerally must be color filtered to produce white light. In addition, incontrast to the white light produced by a white-LED-based BLU, the whitelight produced by the combination of BLU 210 and QD substrate 220 allowsfor an improved color gamut, since the wavelengths of the green and redcomponents can be selected by quantum dot geometry to be more saturatedcolors. This is because the more saturated red and green light generatedby BLU 210 (in conjunction with QD substrate 220) enable a significantlywider gamut to be realized than when using the filtered red and greenlight available from white-LED-based light sources.

In the embodiment illustrated in FIGS. 2 and 3, QD substrate 220 isdepicted as a separate structure from BLU 210. In some embodiments,however, QD substrate 220 may be included as an additional layer of BLU210. In such embodiments, polarizing filter 213 may be positionedbetween QD substrate 220 and light guide plate 214, or between QDsubstrate 220 and LC panel 240. Alternatively, QD substrate 220 may beincorporated into one of the elements of BLU 210, such as polarizingfilter 213, diffuser film 215, or prism film 216. A suitableconfiguration of QD substrate 220 can be acquired from variousmanufacturers, including, but not limited to, 3M and Dow Chemical.

Color filter assembly 230 includes a filter that is configured as ashort-wavelength pass filter with a passband configured to transmitlight having a wavelength that falls within multiple predeterminedwavelength ranges, thereby selectively passing light of a small range ofcolors while reflecting other colors. For example, in some embodiments,color filter assembly 230 is configured to be substantially transparentto red light (i.e., light having a wavelength at or near 650 nm), greenlight, (i.e., light having a wavelength at or near 510 nm) and bluelight (i.e., light having a wavelength at or near 475 nm), whilereflecting other visible light wavelengths. In some embodiments, colorfilter assembly 230 includes, without limitation, a dichroic filter. Inthe embodiment illustrated in FIGS. 2 and 3, color filter assembly 230is depicted as a single substrate, such as a glass substrate withmultiple coatings or films deposited thereon.

Color filter assembly 230 ensures that the light incident on LC panel240 is white light that is substantially equivalent to the InternationalCommission on Illumination (CIE) Standard Illuminant D65. That is, thedifference in the white light incident on LC panel 240 light and CIEStandard Illuminant D65 is not detectable to the human eye. To that end,the passbands of color filter assembly 230 are selected so that lightthat is emitted by BLU 210 is such white light and passes through colorfilter assembly 230. Thus, a portion of the light emitted by BLU 210 isconverted to preferred frequencies of red and green light by QDsubstrate 220. In some embodiments, the passband of color filterassembly 230 that is associated with red light is generally matched tothe red light emission of QD substrate 220 when illuminated by BLU 210,the passband of color filter assembly 230 that is associated with greenlight is generally matched to the green light emission of QD substrate220 when illuminated by BLU 210, and the passband of color filterassembly 230 that is associated with blue light is generally matched tothe light emitted by BLU 210. Thus, less optical energy is lost comparedto the color filtering associated with white-LED-based BLUs.

In some embodiments, a passband of color filter assembly 230 isconsidered to be matched to a particular light emission when a peakfrequency of the light emission falls within a passband of the colorfilter, as illustrated in FIG. 4. FIG. 4 is a graph 400 illustrating thespectral power distribution 401 of a light source juxtaposed with themultiple passbands 402A-402C of color filter assembly 230. As shown,passband 402A is in the blue light regime, passband 402B is in the greenlight regime, and passband 402C is in the red light regime. For purposesof illustration, spectral power distribution 401 depicts a spectralpower distribution of a typical blue LED 212. However, the hereindescribed matching of passband 402A to the light emission associatedwith spectral power distribution 401 is equally applicable to thematching of passband 402C of color filter assembly 230 to the red lightemission of QD substrate 220 or the matching of passband 402B of colorfilter assembly 230 to the green light emission of QD substrate 220.This is because the red light emission of QD substrate 220 and the greenlight emission of QD substrate 220 are both narrow-band emissions withdistinctive peak wavelengths.

As shown, spectral power distribution 401 depicts the variation inrelative optical power for a typical blue LED 212, which is anarrow-band light source. For this particular light source, and fornarrow-band light sources in general, such as quantum dots and manyLEDs, spectral power distribution 401 includes a distinct peakwavelength A. Also shown are passbands 402A-402C, which indicate thevarious ranges of wavelengths that can pass through color filterassembly 230, i.e., red light, green light, and blue light. In the bluelight regime, passband 402A extends from a lower wavelength λ₁, forexample and without limitation 440 nm, to an upper wavelength λ₂, forexample and without limitation 470 nm. Because a peak wavelength λ_(P)of blue LEDs 212, in this embodiment, is within passband 402C, thepassband is considered “matched to” or “tuned to” the light sourceassociated with spectral power distribution 401 and vice versa.Consequently, the majority of optical energy associated with the lightsource (i.e., blue LEDs 212) passes through color filter assembly 230and is not lost.

Similarly, when passband 402B is suitably matched to the green lightemissions of QD substrate 220, the majority of optical energy associatedwith the green light emissions of QD substrate 220 is not attenuated.Furthermore, when passband 402C is suitably matched to the red lightemissions of QD substrate 220, the majority of optical energy associatedwith the red light emissions of QD substrate 220 is not attenuated.

It is noted that while spectral power distribution 401 may be consideredqualitatively representative of a spectral power distribution associatedwith the red light emission of QD substrate 220, the green lightemission of QD substrate 220, or blue light emitted by BLU 210, spectralpower distribution 401 varies significantly from the spectral powerdistribution of a typical white LED light source. For reference,spectral power distribution 403 of a typical white LED light source isalso depicted in FIG. 4. As shown, spectral power distribution 403includes a peak wavelength λ₃ approximately corresponding to blue light,and a broad secondary peak 404, that does not correspond to either greenlight (at ca. 510 nm) or red light (at ca. 650 nm). Consequently,neither passband 402B (associated with passing green light) of colorfilter assembly 230 nor passband 402C (associated with passing redlight) of color filter assembly 230 can be matched to the light emittedby a white LED light source.

In some embodiments, the above-described matching of passband 402B andthe green light emission of QD substrate 220 may be accomplished bydesigning passband 402B to correspond to wavelengths of the green lightemission of QD substrate 220 when illuminated by BLU 210. In otherembodiments, the configuration of quantum dots of QD substrate 220(e.g., quantum dot size, shape, and/or composition) may be selected sothat wavelengths of the green light emission of QD substrate 220, whenilluminated by BLU 210, correspond to passband 402B. In yet otherembodiments, both passband 402B and the configuration of quantum dots ofQD substrate 220 are selected to correspond to a target wavelength band,such as a wavelength or wavelengths of green light that enhance thecolor gamut of display device 150. The matching of passband 402C and thered light emission of QD substrate 220 may be similarly accomplished.

Returning now to FIGS. 2 and 3, LC panel 240 is the liquid-crystalportion of display device 150, and may be a thin-film-transistorliquid-crystal display (TFT LCD). LC panel 240 is configured to generateimages for display by selectively allowing a targeted quantity of lightthrough each subpixel of LC panel 240. For example, and withoutlimitation, each subpixel of LC panel 240 may include, withoutlimitation, a liquid crystal that controls the intensity of lightallowed to pass though the subpixel. Liquid crystals suitable for use inLC panel 240 include, without limitation, a twisted nematic liquidcrystal, a multi domain view alignment (MVA) liquid crystal, or anin-panel switching IPS type liquid crystal. In some embodiments, atouch-sensitive panel or other gesture-sensitive structure configuredfor receiving various input techniques (for example and withoutlimitation, infra-red touch or other like techniques) may be disposed onthe outer surface of LC panel 240.

LC panel 240 also includes, without limitation, a color subpixel arraythat defines the color of each subpixel of LC panel 240, where eachpixel includes a red, green, and blue subpixel. The color subpixel arrayincludes, without limitation, a plurality of red, green, and blue colorfilters that are arranged to overlay the subpixels of LC panel 240.Generally, the color filter array of LC panel 240 is formed on a singlesubstrate, and is configured so that a red filter is aligned with eachred sub-pixel of LC panel 240, a green filter is aligned with each greensub-pixel of LC panel 240, and a blue filter is aligned with each bluesub-pixel of LC panel 240. The wavelength band associated respectivelywith the red, green, and blue filters of the color subpixel array isgenerally selected so that when a maximum intensity of light from BLU210 is allowed to pass through all three light filters of a particularpixel of LC panel 240, white light is generated that corresponds asclosely as practicable to the CIE Standard Illuminant D65.

FIG. 5 is a block diagram illustrating vehicular infotainment system 100in communication with an electronic control module (ECM) 501 of avehicle, according to the various embodiments. As shown, in someembodiments, vehicular infotainment system 100 is in communication withan electronic control module 501 that is associated with a vehicle thatincludes vehicular infotainment system 100. In addition, electroniccontrol module 501 is further in communication with an actuator 502 thatis also associated with the vehicle. Actuator 502 may be incorporated ina key fob associated with the vehicle, an ignition switch for thevehicle, or the like. The key fob may be configured to implement remotekeyless entry, which also signals activation of the ECM. Alternatively,the key fob may include a physical key which engages with the ignitionswitch and in turn activates the ECM. Upon receiving a signal fromactuator 502, ECM 501 may transmit a “wake signal” to vehicularinfotainment system 100, such that BLU 210 in display device 150 ispowered on. This arrangement provides for an enhanced infotainmentdisplay in a vehicle that can withstand the extreme temperature andhumidity conditions that may be experienced in the vehicle.

In some embodiments, a display device includes a nanocrystal material isdisposed on an output surface of a light source, rather than on a filmdisposed adjacent to a color filter assembly and an LC panel. In suchembodiments, the quantity of nanocrystal material employed in thedisplay device is greatly reduced and the efficiency of blue lightconversion is increased. One such embodiment is illustrated in FIGS. 6and 7.

FIG. 6 is an exploded view of a display device 650, according to thevarious embodiments. FIG. 7 is a partial schematic side view of displaydevice 650, according to the various embodiments. Display device 650 issubstantially similar to display device 150 in FIGS. 2 and 3, andtherefore includes color filter assembly 230, LC panel 240, and a BLU610 similar to BLU 210. However, unlike BLU 210, BLU 610 of displaydevice 650 includes a nanocrystal material 701 that is disposed on anoutput surface of a blue LED light source 612. For example, inembodiments in which blue LED light source 612 is an array of multipleblue LEDs, nanocrystal material 701 can be disposed on an output oremission surface of the array. By contrast, display device 150 includesa QD-impregnated film that is included in the stack of layers formingdisplay device 150, i.e., QD material 220 (shown in FIG. 2).

BLU 610 includes, without limitation, back panel 211, blue LED lightsource 612, polarizing filter 213, light guide plate 214, diffuser film215, prism film 216, and reflector panel 219. Blue LED light source 612is disposed along one or more edges of back panel 211 and includes oneor more blue LEDs, such as blue LEDs 212.

Blue LED light source 612 generates blue output light (not shown forclarity) that is immediately or almost immediately incident onnanocrystal material 701. Similar to the above-described QD substrate220, nanocrystal material 701 is configured to convert part of the lightemitted by blue LED light source 612 into relatively pure green light711 and red light 712 by the appropriately configured quantum dots, andtransmit a remainder portion 713 of the blue light generated by blue LEDlight source 612. In this way, an efficient display with enhanced colorproperties is enabled. It is noted that the blue light generated by blueLED light source 612 is converted to green light 711 and red light 712before transmission through the various downstream components of displaydevice 650, including polarizing filter 213, light guide plate 214,diffuser film 215, and prism film 216. Consequently, green light 711 andred light 712 are generated prior to the significant optical losses thatoccur as light is transmitted though polarizing filter 213, light guideplate 214, diffuser film 215, and prism film 216, thereby improvingefficiency of light conversion by nanocrystal material 701.

In the embodiment illustrated in FIG. 6, blue LED light source 612includes a plurality of blue LEDs arranged, for example, as an LED lightbar. In such embodiments, nanocrystal material 701 may be a film thatincludes quantum dots or other nanocrystal structures, and is formed onan output surface 602 of blue LED light source 612. For example,nanocrystal material 701 may be a film on which quantum dots or othernanocrystal structures are formed or deposited. Alternatively oradditionally, nanocrystal material 701 may be a film in which quantumdots or other nanocrystal structures are embedded. In either case,nanocrystal material 701 may be configured as an adhesive film that isattached to output surface 602. Alternatively, nanocrystal material 701may be a film or other nanocrystal material disposed between outputsurface 602 and light guide plate 214.

In the embodiment illustrated in FIGS. 6 and 7, nanocrystal material 701is configured as a single film disposed on output surface 602 of blueLED light source 612. In other embodiments, a nanocrystal material maybe deposited on an output surface of each blue LED included in blue LEDlight source 612. Various embodiments are illustrated in FIGS. 8A-8C.

FIG. 8A is a partial schematic side view of an augmented blue LED 800that includes a quantum dot layer formed within an LED assembly,according to the various embodiments. Augmented blue LED 800 is an LEDdevice that is configured to generate green light 711, red light 712,and remainder portion 713 of a blue LED light source that can beemployed in a display device. Augmented blue LED 800 includes asemiconductor die 801 and reflectors 802 formed on a surface of a body810. In addition, augmented blue LED 800 includes a transparent case 803disposed on body 810 that covers and protects semiconductor die 801 andreflectors 802. Augmented blue LED 800 further includes a quantum dotlayer 805.

Semiconductor die 801 includes one or more LED devices configured toemit blue light, for example having a wavelength between about 450 nmand about 495 nm. Reflectors 802 direct light emitted by semiconductordie 801 away from augmented blue LED 800, for example toward a lightguide plate of a display device. Reflectors 802 form a reflecting cavity804 that may be filled with a transparent encapsulant or may be an emptycavity. Transparent case 803 may be formed from an epoxy, plastic, orany other suitable material that is transparent to light emitted fromsemiconductor die 801 and, in some embodiments, to light emitted byquantum dot layer 805. In some embodiments, transparent case 803 is alsoconfigured as a lens to direct and/or concentrate light emitted bysemiconductor die 801 as appropriate.

Quantum dot layer 805 includes appropriately configured quantum dots orother nanocrystal structures for converting blue light emitted bysemiconductor die 801 into green light 711 and red light 712. Quantumdot layer 805 may have any suitable configuration that positions quantumdots or other nanocrystal structures in the path of light emitted bysemiconductor die 811. In some embodiments, reflecting cavity 804 may befilled with a transparent encapsulant and quantum dot layer 805 may beformed via the deposition of quantum dots onto the transparentencapsulant. Alternatively, in some embodiments, quantum dot layer 805may include a quantum dot-containing film that is applied to thetransparent encapsulant. Alternatively, in some embodiments quantum dotlayer 805 may include a plate on which quantum dots or other nanocrystalstructures are deposited or in which quantum dots or other nanocrystalstructures are embedded. Alternatively, in some embodiments quantum dotlayer 805 may be formed directly on a light-emitting surface 801A ofsemiconductor die 801, for example via sputter deposition.

FIG. 8B is a partial schematic side view of an augmented blue LED 820that includes a quantum dot layer formed on an outer surface of an LEDassembly, according to the various embodiments. Augmented blue LED 820is substantially similar to augmented blue LED 800 of FIG. 8A, exceptthat augmented blue LED 820 does not include a quantum dot layer formedwithin transparent case 803 or on semiconductor die 801, as is the casewith quantum dot layer 805. Instead, augmented blue LED 820 includes aquantum dot layer 825 formed on an outer surface 803A of transparentcase 803. In some embodiments, quantum dot layer 825 is a layer ofmaterial that is deposited on outer surface 803A and includes quantumdots and/or other nanocrystal structures for converting incident bluelight into green light 711 and red light 712. Alternatively, quantum dotlayer 825 may include a film with quantum dots and/or other nanocrystalstructures embedded within that is applied to outer surface 803A.

FIG. 8C is a partial schematic side view of an augmented blue LED 830that includes quantum dots or crystals formed within a transparent caseof an LED assembly, according to the various embodiments. Augmented blueLED 830 is substantially similar to augmented blue LED 800 of FIG. 8A,except that augmented blue LED 830 does not include a quantum dot layerformed within transparent case 803 or on semiconductor die 801, as isthe case with quantum dot layer 805. Instead, some or all of atransparent case 833 includes quantum dots and/or nanocrystal structures835 embedded within. As shown, quantum dots and/or nanocrystalstructures 835 convert a portion of blue light emitted fromsemiconductor die 801 into green light 711 and red light 712, and allowremainder portion 713 to be and transmitted through transparent case833.

In some embodiments, the blue LED light source of a display device ispositioned away from the touch-sensitive surface of the display device,reducing heating of the touch surface along the edge or edges of thedisplay device. As a result, the touch-sensitive surface of the displayscreen is significantly reduced in temperature during operation, therebypreventing or reducing the “hot finger” effect. Thus, the userexperience is improved, and thermal stress on sensitive components ofthe display device is lowered, extending the lifetime of the displaydevice.

In some embodiments, the blue LED light source of a display device ispositioned away from the touch-sensitive surface of the display devicevia a curved light guide, as shown in FIG. 9. FIG. 9 is a partialschematic side view of a display device 950 that includes a curved lightguide plate 914, according to the various embodiments. With theexception of curved light guide plate 914, display device 950 is similarin configuration and operation to display device 650 in FIGS. 6 and 7.

Curved light guide plate 914 includes an elbow portion 901 and a planarportion 902 that are optically coupled to each other. Elbow portion 901enables light emitted by blue LED light source 612 to enter curved lightguide plate 914 while traveling in one direction, and to be transmittedinto and through planar portion 902 of curved light guide plate 914 inanother direction, i.e., in the plane of planar portion 902.Consequently, blue LED light source 612 can be positioned remotely fromthe touch-sensitive surface (not shown in FIG. 9) of display device 950,and outside of a region defined between (i) a first plane defined by afront surface of planar portion 902, and (ii) a second plane defined bya rear surface of planar portion 902 that opposes the front surface. Forexample, in the embodiment illustrated in FIG. 9, elbow portion 901enables blue LED light source 612 to be mounted on a printed circuitboard 903 that is positioned remote from and substantially parallel toplanar portion 902. In some embodiments, printed circuit board 903 islocated external to back panel 211 as shown, thereby further reducingthermal stress on temperature-sensitive components of display device950. In other embodiments, printed circuit board 903 is locatedinternally in back panel 211, but is still more remote from thetouch-sensitive surface of display device 950 than blue LED light source612 is from the touch-sensitive surface of display device 650, as shownin FIGS. 6 and 7.

In the embodiment illustrated in FIG. 9, elbow portion 901 includes a90-degree bend. In other embodiments, elbow portion 901 can include abend of any suitable angle, up to and including 180 degrees or more. Insuch embodiments, elbow portion 901 can be configured to transmit lightthat enters curved light guide plate 914 (at a surface 904) to planarportion 902 via total internal reflection (TIR). For example, greenlight 711, red light 712, and remainder portion 713 are emitted by blueLED light source 612 and nanocrystal material 701, are generallydirected towards surface 904. Green light 711, red light 712, andremainder portion 713 are then transmitted through elbow 901 via TIRinto planar portion 902. In such embodiments, light guide plate 914 canbe formed from any suitable optically transparent material that enablesTIR of light incident on surface 904 into planar portion 902.Alternatively, in some embodiments, elbow portion 901 includes a prismor any other suitable optical element or elements that enable lightincident on surface 904 to be transmitted along planar portion 902 ofcurved light guide plate 914.

In some embodiments, the blue LED light source of a display device ispositioned away from the touch-sensitive surface of the display deviceby arranging the blue LEDs of the blue LED light source in a planararray 1002 of blue LEDs 1012, as shown in FIG. 10. FIG. 10 is a partialschematic side view of a display device 1050 that includes a planararray 1002, according to the various embodiments. Display device 1050 issimilar in configuration and operation to display device 650 in FIGS. 6and 7, with the exception of the addition of planar array 1002 and theremoval of blue LED light source 612, light guide plate 214, andreflector panel 219.

Planar array 1002 includes a plurality of blue LEDs 1012 that can besubstantially similar to blue LEDs 212 in FIG. 2. Blue LEDs 1012 emitblue light 1004 that is directed to diffuser film 215, prism film 216,and polarizing filter 213 of back panel 211 as shown. After passingthrough diffuser film 215, prism film 216, and polarizing filter 213,blue light 1004 is incident on QD substrate 220, so that green light711, red light 712, and remainder portion 713 are emitted and directedtoward color filter assembly 230 (not shown) and LC panel 240 (notshown). Blue LEDs 1012 are located more remotely from thetouch-sensitive surface of display device 1050 than the LEDs of blue LEDlight source 612. In addition, blue LEDs 1012 are distributed across alarger area than the blue LEDs of blue LED light source 612.Consequently, for both of these reasons, the touch-sensitive surface ofdisplay device 1050 undergoes less heating and thermal stress than thatof a display device that includes a blue LED light source disposed onone or more edges of the display device.

In some embodiments, planar array 1002 is mounted on a printed circuitboard 1003 that is positioned substantially parallel to back panel 211.In some embodiments, printed circuit board 1003 is located external toback panel 211 as shown, thereby further reducing thermal stress ontemperature-sensitive components of display device 1050. In otherembodiments, printed circuit board 1003 is located internally in backpanel 211, but is still more remote from the touch-sensitive surface ofdisplay device 1050 than blue LED light source 612 is from thetouch-sensitive surface of display device 650, as shown in FIGS. 6 and7.

In some embodiments, a planar array of blue LEDs generates green light711, red light 712, and remainder portion 713 directly, as shown in FIG.11. FIG. 11 is a partial schematic side view of a display device 1150that includes a planar array 1102, according to the various embodiments.Display device 1150 is similar in configuration and operation to displaydevice 1050 in FIG. 10, with the exception of the addition of ananocrystal material 1101 that is disposed on an output surface of eachof blue LEDs 1012. Nanocrystal material 1101 can be substantiallysimilar to nanocrystal material 701 of FIG. 7, quantum dot layer 805 ofFIG. 8A, quantum dot layer 825 of FIG. 8B, quantum dots and/ornanocrystal structures 835 of FIG. 8C, or any other suitable quantum dotor nanocrystal material. Consequently, when blue LEDs 1012 emit bluelight, green light 711 and red light 712 are generated by nanocrystalmaterial 1101, and remainder portion 713 is transmitted throughnanocrystal material 1101.

In sum, various embodiments set forth systems and techniques for a widecolor gamut LCD display device for a vehicle infotainment system withreduced heating of the display surface. The display device includes ablue-LED-based light source and a quantum-dot material configured toconvert a portion of the light emitted by the blue-LED-based lightsource into a red light emission and a green light emission. In someembodiments, the quantum-dot material is formed on an output surface ofthe blue-LED-based light source, such as a light-emitting surface of ablue LED or an output lens or other outer surface of an array of blueLEDs. In some embodiments, a curved light guide plate enables theblue-LED-based light source to be disposed remotely from atouch-sensitive surface of the display device, and in some embodimentsoutside of a region defined a first plane defined by a front surface ofthe planar light guide that is optically coupled to the light-receivingsurface of a liquid crystal module and a second plane defined by a rearsurface of the planar light guide that opposes the front surface.Further, in some embodiments, the blue-LED-based light source isconfigured as a planar array of blue LEDs that is disposed more remotelyfrom the touch-sensitive light source and distributes the blue LEDsacross a larger area of the touch-sensitive light source than when anarray of LEDs is disposed on an edge region of the display device.

Advantageously, in some embodiments, the quantum-dot material isdisposed on an output surface of the blue-LED-based light source,thereby enabling improved efficiency of light conversion using lessquantum-dot material. Furthermore, in some embodiments, theblue-LED-based light source is positioned away from the touch surface ofthe display device via a curved light guide, reducing the temperature ofthe touch surface during operation.

1. In some embodiments, a display device comprises a planar array ofblue light-emitting diodes (LEDs) that are each configured to generate ablue output light, wherein the planar array is positioned parallel to alight-receiving surface of a liquid crystal module; a nanocrystalmaterial that is disposed between the planar array and the liquidcrystal module, the nanocrystal material configured to: receive the blueoutput light, convert a first portion of the blue output light to agreen light emission, convert a second portion of the blue output lightto a red light emission, and transmit a remainder portion of the blueoutput light; and the liquid crystal module, which is configured toreceive the green light emission, the red light emission, and theremainder portion of the blue output light and generate an image thatincludes a portion of the green light emission, a portion of the redlight emission, and a portion of the remainder portion of the blueoutput light.

2. The display device of clause 1, wherein the blue output light isemitted toward the light-receiving surface of the liquid crystal module.

3. The display device of clauses 1 or 2, wherein each blue LED includedin the planar array of blue LEDs is mounted on a first printed circuitboard.

4. The display device of any of clauses 1-3, wherein the nanocrystalmaterial is disposed on an outer surface of the planar array.

5. The display device of any of clauses 1-4, wherein the nanocrystalmaterial is formed as a continuous film that is disposed between theplanar array and a liquid crystal module.

6. The display device of any of clauses 1-5, wherein the nanocrystalmaterial is disposed on a light-emitting surface of each of the blueLEDs.

7. The display device of any of clauses 1-6, wherein each blue LEDincluded in the planar array of blue LEDs comprises a transparentencapsulant, and the nanocrystal material is disposed within thetransparent encapsulant.

8. The display device of any of clauses 1-7, wherein each blue LEDincluded in the planar array of blue LEDs comprises a transparentencapsulant, and the nanocrystal material is disposed on a surface ofthe transparent encapsulant.

9. The display device of any of clauses 1-8, wherein the nanocrystalmaterial is disposed between the transparent encapsulant and the blueLED.

10. The display device of any of clauses 1-9, wherein the nanocrystalmaterial is disposed on an outer surface of the transparent encapsulant.

11. In some embodiments, a vehicle infotainment system comprises: aprocessor configured to generate digital images; and a display devicefor displaying the digital images that includes: a planar array ofmultiple blue light-emitting diodes (LEDs) that are each configured togenerate a blue output light, wherein the planar array is positionedparallel to a light-receiving surface of a liquid crystal module; ananocrystal material that is disposed between the planar array and aliquid crystal module, the nanocrystal material configured to: receivethe blue output light, convert a first portion of the blue output lightto a green light emission, convert a second portion of the blue outputlight to a red light emission, and transmit a remainder portion of theblue output light; and a liquid crystal module configured to receive thegreen light emission, the red light emission, and the remainder portionof the blue output light and generate an image that includes a portionof the green light emission, a portion of the red light emission, and aportion of the remainder portion of the blue output light.

12. The display device of clause 11, wherein the nanocrystal material isdisposed on an outer surface of the planar array.

13. The display device of clauses 11 or 12, wherein the nanocrystalmaterial is formed as a continuous film that is disposed between theplanar array and a liquid crystal module.

14. The display device of any of clauses 11-13, wherein the nanocrystalmaterial is disposed on a light-emitting surface of each of the blueLEDs.

15. The display device of any of clauses 11-14, wherein each blue LEDincluded in the planar array of blue LEDs comprises a transparentencapsulant, and the nanocrystal material is disposed within thetransparent encapsulant.

16. The display device of any of clauses 11-15, wherein each blue LEDincluded in the planar array of blue LEDs comprises a transparentencapsulant, and the nanocrystal material is disposed on a surface ofthe transparent encapsulant.

17. The display device of any of clauses 11-16, wherein the nanocrystalmaterial is disposed on an outer surface of the transparent encapsulant.

18. The display device of any of clauses 11-17, wherein the nano-crystalmaterial includes at least one of quantum dots and quantum rods.

19. The display device of any of clauses 11-18, wherein in combination,the red light emission, the green light emission, and the remainderportion of the blue output light produce a white light substantiallyequivalent to International Commission on Illumination (CIE) StandardIlluminant D65.

20. In some embodiments, a display device comprises: a planar array ofblue light-emitting diodes (LEDs) that are each configured to generate ablue output light, wherein the planar array is configured to emit theblue output light toward a light-receiving surface of a liquid crystalmodule; a nanocrystal material that is disposed between the planar arrayand the liquid crystal module, the nanocrystal material configured to:receive the blue output light, convert a first portion of the blueoutput light to a green light emission, convert a second portion of theblue output light to a red light emission, and transmit a remainderportion of the blue output light; and the liquid crystal module, whichis configured to receive the green light emission, the red lightemission, and the remainder portion of the blue output light andgenerate an image that includes a portion of the green light emission, aportion of the red light emission, and a portion of the remainderportion of the blue output light.

Any and all combinations of any of the claim elements recited in any ofthe claims and/or any elements described in this application, in anyfashion, fall within the contemplated scope of the present invention andprotection.

The descriptions of the various embodiments have been presented forpurposes of illustration, but are not intended to be exhaustive orlimited to the embodiments disclosed. Many modifications and variationswill be apparent to those of ordinary skill in the art without departingfrom the scope and spirit of the described embodiments.

The block diagrams in the figures illustrate the architecture,functionality, and operation of possible implementations of systemsaccording to various embodiments of the present disclosure.

While the preceding is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

The claimed invention is:
 1. A display device, comprising: an array ofblue light-emitting diodes (LEDs) that are each configured to generate ablue output light; a nanocrystal material that is disposed at a firstposition along a path of light from the array of blue LEDs to a liquidcrystal module, the nanocrystal material configured to receive the blueoutput light, wherein at least a first portion of the nanocrystalmaterial is configured based on one of a first shape and converts afirst portion of the blue output light to a green light emission havinga first peak wavelength, wherein at least a second portion of thenanocrystal material is configured based on a second shape and convertsa second portion of the blue output light to a red light emission havinga second peak wavelength, wherein the second shape is different from thefirst shape, and wherein at least a third portion of the nanocrystalmaterial is configured to transmit a remainder portion of the blueoutput light; a color filter assembly disposed at a second positionalong the path of light, wherein the second position is located along apath from the first position to the liquid crystal module, wherein thecolor filter assembly is configured with a first passband that isconfigured to match the first peak wavelength, a second passband that isconfigured to match the second peak wavelength, and a third passbandthat includes a peak wavelength of the remainder portion of the blueoutput light; and the liquid crystal module, which is configured toreceive the green light emission passed through the color filterassembly, the red light emission passed through the color filterassembly, and the remainder portion of the blue output light passedthrough the color filter assembly and generate an image that includes aportion of the green light emission, a portion of the red lightemission, and a portion of the remainder portion of the blue outputlight, wherein the first position at which the nanocrystal material isdisposed comprises an outer surface of at least one blue LED included inthe array of blue LEDs and forms an outermost surface of an LED assemblyin which the at least one blue LED is disposed.
 2. The display device ofclaim 1, wherein the blue output light is emitted toward alight-receiving surface of the liquid crystal module.
 3. The displaydevice of claim 1, wherein each blue LED included in the array of blueLEDs is mounted on a first printed circuit board.
 4. The display deviceof claim 1, wherein the nanocrystal material is disposed on an outersurface of the array.
 5. The display device of claim 1, wherein thenanocrystal material is formed as a continuous film that is disposed atthe first position.
 6. The display device of claim 1, wherein the firstposition at which the nanocrystal material is disposed comprises alight-emitting surface of each of the blue LEDs.
 7. A vehicleinfotainment system, comprising: a processor configured to generatedigital images; and a display device for displaying the digital imagesthat includes: an array of multiple blue light-emitting diodes (LEDs)that are each configured to generate a blue output light; a nanocrystalmaterial that is disposed at a first position along a path of light fromthe array of blue LEDs to a liquid crystal module, the nanocrystalmaterial configured to receive the blue output light, wherein at least afirst portion of the nanocrystal material is configured based on a firstshape and converts a first portion of the blue output light to a greenlight emission having a first peak wavelength, wherein at least a secondportion of the nanocrystal material is configured based on a secondshape and converts a second portion of the blue output light to a redlight emission having a second peak wavelength, wherein the second shapeis different from the first shape, and wherein at least a third portionof the nanocrystal material is configured to transmit a remainderportion of the blue output light; a color filter assembly disposed at asecond position along the path of light, wherein the second position islocated along a path from the first position to the liquid crystalmodule, wherein the color filter assembly is configured with a firstpassband that is configured to match the first peak wavelength, a secondpassband that is configured to match the second peak wavelength, and athird passband that includes a peak wavelength of the remainder portionof the blue output light; and the liquid crystal module configured toreceive the green light emission passed through the color filterassembly, the red light emission passed through the color filterassembly, and the remainder portion of the blue output light passedthrough the color filter assembly and generate an image that includes aportion of the green light emission, a portion of the red lightemission, and a portion of the remainder portion of the blue outputlight, wherein the first position at which the nanocrystal material isdisposed comprises an outer surface of at least one blue LED included inthe array of blue LEDs and forms an outermost surface of an LED assemblyin which the at least one blue LED is disposed.
 8. The display device ofclaim 7, wherein the nanocrystal material is disposed on an outersurface of the array.
 9. The display device of claim 7, wherein thenanocrystal material is formed as a continuous film that is disposed atthe first position.
 10. The display device of claim 7, wherein the firstposition at which the nanocrystal material is disposed comprises alight-emitting surface of each of the blue LEDs.
 11. The display deviceof claim 7, wherein the nanocrystal material includes at least one ofquantum dots or quantum rods.
 12. The display device of claim 7, whereinin combination, the red light emission, the green light emission, andthe remainder portion of the blue output light produce a white lightsubstantially equivalent to International Commission on Illumination(CIE) Standard Illuminant D65.
 13. A display device, comprising: anarray of blue light-emitting diodes (LEDs) that are each configured togenerate a blue output light; a nanocrystal material that is disposed ata first position along a path of light from the array of blue LEDs to aliquid crystal module, the nanocrystal material configured to receivethe blue output light, wherein at least a first portion of thenanocrystal material is configured based on a first shape and converts afirst portion of the blue output light to a green light emission havinga first peak wavelength, wherein at least a second portion of thenanocrystal material is configured based on a second shape and convertsa second portion of the blue output light to a red light emission havinga second peak wavelength, wherein the second shape is different from thefirst shape, and wherein at least a third portion of the nanocrystalmaterial is configured to transmit a remainder portion of the blueoutput light; a color filter assembly disposed at a second positionalong the path of light, wherein the second position is located along apath from the first position to the liquid crystal module, wherein thecolor filter assembly is configured with a first passband that isconfigured to match the first peak wavelength, a second passband that isconfigured to match the second peak wavelength, and a third passbandthat includes a peak wavelength of the remainder portion of the blueoutput light; and the liquid crystal module, which is configured toreceive the green light emission passed through the color filterassembly, the red light emission passed through the color filterassembly, and the remainder portion of the blue output light passedthrough the color filter assembly and generate an image that includes aportion of the green light emission, a portion of the red lightemission, and a portion of the remainder portion of the blue outputlight, wherein the first position at which the nanocrystal material isdisposed comprises an outer surface of at least one blue LED included inthe array of blue LEDs and forms an outermost surface of an LED assemblyin which the at least one blue LED is disposed.